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Increase in gamma-glutamyltransferase by glutathione depletion in rat type II pneumocytes.
Free Radic Biol Med. 1997; 22(3):525-34.FR

Abstract

The purpose of our study was to investigate the effect of oxidative stress or intracellular glutathione (GSH) depletion on gamma-glutamyltransferase (gamma-GT) activity in cultured type II pneumocytes. Twenty-four hours after isolation, primary cultures of rat type II pneumocytes were preincubated with one of four compounds: 15, 30, 60, 125, 250 microM L-buthionine-[SR]-sulfoximine (BSO) for 3 h; 100, 200, 400, 800 microM tertiary-butylhydroperoxide (t-BOOH) for 45 min; 10, 25, 50, 100 microM menadione for 15 min; 100, 1000 microM paraquat for 1 h. GSH levels, H2O2 and O2.- generation were measured immediately after the incubation, gamma-GT activity and GSH levels also up to 24 h or 48 h later. Exposure to BSO led to a persistent GSH depletion without increase in H2O2 or O2.- production, together with a dose and time-dependent increase (doubling) of gamma-GT activity with a nonsignificant increase in gamma-GT mRNA expression 24 h after exposure to BSO. Exposure to 100 microM menadione, which increased H2O2 production, decreased gamma-GT activity. t-BOOH or paraquat did not give rise to a measurable increase in H2O2 or O2.-. Paraquat did not affect initial GSH levels, but increased GSH and decreased gamma-GT activity 24 h later. t-BOOH (400 and 800 microM) initially decreased GSH, and tended to increase GSH 24 h later, 100 and 200 microM increased gamma-GT activity 24 h later, but 800 microM decreased it. Restoration of intracellular GSH levels by addition of GSH to the culture medium completely prevented the increase in gamma-GT activity by BSO, while the addition of catalase or DMTU had no effect. We conclude that at least two effects are operating upon gamma-GT activity: GSH depletion seems to increase gamma-GT activity, while exposure to compounds generating oxidative stress correlates with a decrease in gamma-GT activity.

Authors+Show Affiliations

Laboratory of Pneumology, K.U. Leuven, Belgium.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

8981045

Citation

van Klaveren, R J., et al. "Increase in Gamma-glutamyltransferase By Glutathione Depletion in Rat Type II Pneumocytes." Free Radical Biology & Medicine, vol. 22, no. 3, 1997, pp. 525-34.
van Klaveren RJ, Hoet PH, Pype JL, et al. Increase in gamma-glutamyltransferase by glutathione depletion in rat type II pneumocytes. Free Radic Biol Med. 1997;22(3):525-34.
van Klaveren, R. J., Hoet, P. H., Pype, J. L., Demedts, M., & Nemery, B. (1997). Increase in gamma-glutamyltransferase by glutathione depletion in rat type II pneumocytes. Free Radical Biology & Medicine, 22(3), 525-34.
van Klaveren RJ, et al. Increase in Gamma-glutamyltransferase By Glutathione Depletion in Rat Type II Pneumocytes. Free Radic Biol Med. 1997;22(3):525-34. PubMed PMID: 8981045.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Increase in gamma-glutamyltransferase by glutathione depletion in rat type II pneumocytes. AU - van Klaveren,R J, AU - Hoet,P H, AU - Pype,J L, AU - Demedts,M, AU - Nemery,B, PY - 1997/1/1/pubmed PY - 1997/1/1/medline PY - 1997/1/1/entrez SP - 525 EP - 34 JF - Free radical biology & medicine JO - Free Radic. Biol. Med. VL - 22 IS - 3 N2 - The purpose of our study was to investigate the effect of oxidative stress or intracellular glutathione (GSH) depletion on gamma-glutamyltransferase (gamma-GT) activity in cultured type II pneumocytes. Twenty-four hours after isolation, primary cultures of rat type II pneumocytes were preincubated with one of four compounds: 15, 30, 60, 125, 250 microM L-buthionine-[SR]-sulfoximine (BSO) for 3 h; 100, 200, 400, 800 microM tertiary-butylhydroperoxide (t-BOOH) for 45 min; 10, 25, 50, 100 microM menadione for 15 min; 100, 1000 microM paraquat for 1 h. GSH levels, H2O2 and O2.- generation were measured immediately after the incubation, gamma-GT activity and GSH levels also up to 24 h or 48 h later. Exposure to BSO led to a persistent GSH depletion without increase in H2O2 or O2.- production, together with a dose and time-dependent increase (doubling) of gamma-GT activity with a nonsignificant increase in gamma-GT mRNA expression 24 h after exposure to BSO. Exposure to 100 microM menadione, which increased H2O2 production, decreased gamma-GT activity. t-BOOH or paraquat did not give rise to a measurable increase in H2O2 or O2.-. Paraquat did not affect initial GSH levels, but increased GSH and decreased gamma-GT activity 24 h later. t-BOOH (400 and 800 microM) initially decreased GSH, and tended to increase GSH 24 h later, 100 and 200 microM increased gamma-GT activity 24 h later, but 800 microM decreased it. Restoration of intracellular GSH levels by addition of GSH to the culture medium completely prevented the increase in gamma-GT activity by BSO, while the addition of catalase or DMTU had no effect. We conclude that at least two effects are operating upon gamma-GT activity: GSH depletion seems to increase gamma-GT activity, while exposure to compounds generating oxidative stress correlates with a decrease in gamma-GT activity. SN - 0891-5849 UR - https://www.unboundmedicine.com/medline/citation/8981045/Increase_in_gamma_glutamyltransferase_by_glutathione_depletion_in_rat_type_II_pneumocytes_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0891-5849(96)00375-9 DB - PRIME DP - Unbound Medicine ER -